Chuhe River Basin is located between Jianghuai and is a first-class tributary on the left bank of the lower reaches of the Yangtze River. Originated in Liangyuan hilly area of Feidong County, Anhui Province, its main stream is basically parallel to the eastward flow of the Yangtze River, and it flows through Hefei, Wuhu, Chuzhou, Maanshan and Nanjing in Jiangsu Province along the way, and joins the Yangtze River at Dahekou in Jiangsu Province. The total length of the main stream is 269km, including 197km in Anhui province and 1 16km in Jiangsu province (part of the river reaches are the rivers between the two provinces). The area of Chuhe River basin is about 8057km2, and that of Anhui is 6250km 2, accounting for 78. 1%. Jiangsu 1750km2, accounting for 2 1.9%. The Chuhe River has eight main tributaries, all located on the left bank. From top to bottom, there are Xiaomachang River, Damachang River, Xianghe River, Liuqinghe River, Laian River, He Peihe River, Zaohe River and Babai River in Jiangsu Province. The right bank of Chuhe River is mainly a natural distributary channel or an artificial distributary channel. From top to bottom, it is the Simashan diversion canal, Zhujiashan diversion canal, Macha River diversion canal, Ziyue River and Huazikou River. It can divert the flood from the main stream to the Yangtze River.

There are about 1 15000 dams in the basin with an effective storage capacity of 429 million m3. 585 small reservoirs with an effective storage capacity of 295 million cubic meters; There are 23 large and medium-sized reservoirs with a total storage capacity of101200,000 m 3. The total reservoir control area is 1868. 1km2, accounting for 23.3% of the total basin area, including Huanglishu, Shaheji, Chengxi, Tuncang and Jinniushan watersheds *** 1045km2, with a total storage capacity of 675 million m 3. Irrigation is the main task of most reservoirs, which has a certain effect of flood detention and peak clipping.

There are no lakes for flood storage and detention in the basin, but there are small flood storage and detention depressions (such as Huangcaowei, Haoziwei and Wang Bodang) at the intersection of the main and tributaries, among which Huangcaowei No.2, Huangcaowei No.3, Haoziwei (each in Anhui and Jiangsu provinces/kloc-0) and Wangbodong are four flood storage and detention areas.